[PATCHv2 1/9] gdb: unify parts of the Linux and FreeBSD core dumping code
Andrew Burgess
andrew.burgess@embecosm.com
Tue Feb 9 21:52:40 GMT 2021
* Andrew Burgess <andrew.burgess@embecosm.com> [2021-02-01 11:56:00 +0000]:
> I have pushed this patch only so far as this is a nice clean up in its
> own right.
I have now reverted this patch due to the regressions it introduced,
see here:
https://sourceware.org/pipermail/gdb-patches/2021-February/175750.html
I still plan to bring this patch back as soon as I have a good
solution - I just don't have one immediately, hence the revert.
Any suggestions for good solutions will be appreciated :)
Thanks,
Andrew
---
commit 03642b7189bc0bfdf61354a6d9a3f3e46d82709c
Author: Andrew Burgess <andrew.burgess@embecosm.com>
Date: Tue Feb 9 21:41:30 2021 +0000
gdb: revert "gdb: unify parts of the Linux and FreeBSD core dumping code"
This reverts commit 82a1fd3a4935fe665cf08bc6820942c4a091184c.
It was pointed out:
https://sourceware.org/pipermail/gdb-patches/2021-February/175750.html
that commit 82a1fd3a4935 caused GDB to have an unconditional
dependency on ELF specific parts of BFD. What this means is that if
GDB and BFD are built for a non-elf target then there will be
undefined symbol references within GDB.
The right solution isn't immediately obvious. So rather than rush a
fix in I'm reverting this commit for now, and will bring it back once
I have a good solution.
gdb/ChangeLog:
* gcore.c (struct gcore_collect_regset_section_cb_data): Delete.
(gcore_collect_regset_section_cb): Delete.
(gcore_collect_thread_registers): Delete.
(gcore_build_thread_register_notes): Delete.
(gcore_find_signalled_thread): Delete.
* gcore.h: Remove 'gdbsupport/gdb_signals.h' include and delete
'gdbarch' and 'thread_info' declarations.
(gcore_build_thread_register_notes): Delete declaration.
(gcore_find_signalled_thread): Likewise.
* fbsd-tdep.c: Remove 'gcore.h' include.
(struct fbsd_collect_regset_section_cb_data): New struct.
(fbsd_collect_regset_section_cb): New function.
(fbsd_collect_thread_registers): New function.
(struct fbsd_corefile_thread_data): New struct.
(fbsd_corefile_thread): New function.
(fbsd_make_corefile_notes): Call FreeBSD specific code.
* linux-tdep.c: Remove 'gcore.h' include.
(struct linux_collect_regset_section_cb_data): New struct.
(linux_collect_regset_section_cb): New function.
(linux_collect_thread_registers): New function.
(linux_corefile_thread): Call Linux specific code.
(find_signalled_thread): New function.
(linux_make_corefile_notes): Call find_signalled_thread.
diff --git a/gdb/fbsd-tdep.c b/gdb/fbsd-tdep.c
index edd3edc4220..cc51e921ae2 100644
--- a/gdb/fbsd-tdep.c
+++ b/gdb/fbsd-tdep.c
@@ -32,7 +32,6 @@
#include "elf-bfd.h"
#include "fbsd-tdep.h"
-#include "gcore.h"
/* This enum is derived from FreeBSD's <sys/signal.h>. */
@@ -584,6 +583,129 @@ find_signalled_thread (struct thread_info *info, void *data)
return 0;
}
+/* Structure for passing information from
+ fbsd_collect_thread_registers via an iterator to
+ fbsd_collect_regset_section_cb. */
+
+struct fbsd_collect_regset_section_cb_data
+{
+ fbsd_collect_regset_section_cb_data (const struct regcache *regcache,
+ bfd *obfd,
+ gdb::unique_xmalloc_ptr<char> ¬e_data,
+ int *note_size,
+ unsigned long lwp,
+ gdb_signal stop_signal)
+ : regcache (regcache),
+ obfd (obfd),
+ note_data (note_data),
+ note_size (note_size),
+ lwp (lwp),
+ stop_signal (stop_signal)
+ {}
+
+ const struct regcache *regcache;
+ bfd *obfd;
+ gdb::unique_xmalloc_ptr<char> ¬e_data;
+ int *note_size;
+ unsigned long lwp;
+ enum gdb_signal stop_signal;
+ bool abort_iteration = false;
+};
+
+static void
+fbsd_collect_regset_section_cb (const char *sect_name, int supply_size,
+ int collect_size, const struct regset *regset,
+ const char *human_name, void *cb_data)
+{
+ char *buf;
+ struct fbsd_collect_regset_section_cb_data *data
+ = (struct fbsd_collect_regset_section_cb_data *) cb_data;
+
+ if (data->abort_iteration)
+ return;
+
+ gdb_assert (regset->collect_regset);
+
+ buf = (char *) xmalloc (collect_size);
+ regset->collect_regset (regset, data->regcache, -1, buf, collect_size);
+
+ /* PRSTATUS still needs to be treated specially. */
+ if (strcmp (sect_name, ".reg") == 0)
+ data->note_data.reset (elfcore_write_prstatus
+ (data->obfd, data->note_data.release (),
+ data->note_size, data->lwp,
+ gdb_signal_to_host (data->stop_signal),
+ buf));
+ else
+ data->note_data.reset (elfcore_write_register_note
+ (data->obfd, data->note_data.release (),
+ data->note_size, sect_name, buf,
+ collect_size));
+ xfree (buf);
+
+ if (data->note_data == NULL)
+ data->abort_iteration = true;
+}
+
+/* Records the thread's register state for the corefile note
+ section. */
+
+static void
+fbsd_collect_thread_registers (const struct regcache *regcache,
+ ptid_t ptid, bfd *obfd,
+ gdb::unique_xmalloc_ptr<char> ¬e_data,
+ int *note_size,
+ enum gdb_signal stop_signal)
+{
+ fbsd_collect_regset_section_cb_data data (regcache, obfd, note_data,
+ note_size, ptid.lwp (),
+ stop_signal);
+
+ gdbarch_iterate_over_regset_sections (regcache->arch (),
+ fbsd_collect_regset_section_cb,
+ &data, regcache);
+}
+
+struct fbsd_corefile_thread_data
+{
+ fbsd_corefile_thread_data (struct gdbarch *gdbarch,
+ bfd *obfd,
+ gdb::unique_xmalloc_ptr<char> ¬e_data,
+ int *note_size,
+ gdb_signal stop_signal)
+ : gdbarch (gdbarch),
+ obfd (obfd),
+ note_data (note_data),
+ note_size (note_size),
+ stop_signal (stop_signal)
+ {}
+
+ struct gdbarch *gdbarch;
+ bfd *obfd;
+ gdb::unique_xmalloc_ptr<char> ¬e_data;
+ int *note_size;
+ enum gdb_signal stop_signal;
+};
+
+/* Records the thread's register state for the corefile note
+ section. */
+
+static void
+fbsd_corefile_thread (struct thread_info *info,
+ struct fbsd_corefile_thread_data *args)
+{
+ struct regcache *regcache;
+
+ regcache = get_thread_arch_regcache (info->inf->process_target (),
+ info->ptid, args->gdbarch);
+
+ target_fetch_registers (regcache, -1);
+
+ fbsd_collect_thread_registers (regcache, info->ptid, args->obfd,
+ args->note_data, args->note_size,
+ args->stop_signal);
+}
+
/* Return a byte_vector containing the contents of a core dump note
for the target object of type OBJECT. If STRUCTSIZE is non-zero,
the data is prefixed with a 32-bit integer size to match the format
@@ -660,17 +782,16 @@ fbsd_make_corefile_notes (struct gdbarch *gdbarch, bfd *obfd, int *note_size)
signalled_thr = curr_thr;
}
- gcore_build_thread_register_notes (gdbarch, signalled_thr,
- signalled_thr->suspend.stop_signal,
- obfd, ¬e_data, note_size);
+ fbsd_corefile_thread_data thread_args (gdbarch, obfd, note_data, note_size,
+ signalled_thr->suspend.stop_signal);
+
+ fbsd_corefile_thread (signalled_thr, &thread_args);
for (thread_info *thr : current_inferior ()->non_exited_threads ())
{
if (thr == signalled_thr)
continue;
- gcore_build_thread_register_notes (gdbarch, thr,
- signalled_thr->suspend.stop_signal,
- obfd, ¬e_data, note_size);
+ fbsd_corefile_thread (thr, &thread_args);
}
/* Auxiliary vector. */
diff --git a/gdb/gcore.c b/gdb/gcore.c
index d62aa3a7109..73ac6b09c70 100644
--- a/gdb/gcore.c
+++ b/gdb/gcore.c
@@ -579,142 +579,6 @@ gcore_memory_sections (bfd *obfd)
return 1;
}
-/* Structure for passing information from GCORE_COLLECT_THREAD_REGISTERS
- via an iterator to GCORE_COLLECT_REGSET_SECTION_CB. */
-
-struct gcore_collect_regset_section_cb_data
-{
- gcore_collect_regset_section_cb_data (struct gdbarch *gdbarch,
- const struct regcache *regcache,
- bfd *obfd, ptid_t ptid,
- gdb_signal stop_signal,
- gdb::unique_xmalloc_ptr<char> *note_data,
- int *note_size)
-
- : gdbarch (gdbarch), regcache (regcache), obfd (obfd),
- note_data (note_data), note_size (note_size),
- stop_signal (stop_signal)
- {
- /* The LWP is often not available for bare metal target, in which case
- use the tid instead. */
- if (ptid.lwp_p ())
- lwp = ptid.lwp ();
- else
- lwp = ptid.tid ();
- }
-
- struct gdbarch *gdbarch;
- const struct regcache *regcache;
- bfd *obfd;
- gdb::unique_xmalloc_ptr<char> *note_data;
- int *note_size;
- unsigned long lwp;
- enum gdb_signal stop_signal;
- bool abort_iteration = false;
-};
-
-/* Callback for ITERATE_OVER_REGSET_SECTIONS that records a single
- regset in the core file note section. */
-
-static void
-gcore_collect_regset_section_cb (const char *sect_name, int supply_size,
- int collect_size,
- const struct regset *regset,
- const char *human_name, void *cb_data)
-{
- struct gcore_collect_regset_section_cb_data *data
- = (struct gcore_collect_regset_section_cb_data *) cb_data;
- bool variable_size_section = (regset != NULL
- && regset->flags & REGSET_VARIABLE_SIZE);
-
- gdb_assert (variable_size_section || supply_size == collect_size);
-
- if (data->abort_iteration)
- return;
-
- gdb_assert (regset != nullptr && regset->collect_regset != nullptr);
-
- /* This is intentionally zero-initialized by using std::vector, so
- that any padding bytes in the core file will show as 0. */
- std::vector<gdb_byte> buf (collect_size);
-
- regset->collect_regset (regset, data->regcache, -1, buf.data (),
- collect_size);
-
- /* PRSTATUS still needs to be treated specially. */
- if (strcmp (sect_name, ".reg") == 0)
- data->note_data->reset (elfcore_write_prstatus
- (data->obfd, data->note_data->release (),
- data->note_size, data->lwp,
- gdb_signal_to_host (data->stop_signal),
- buf.data ()));
- else
- data->note_data->reset (elfcore_write_register_note
- (data->obfd, data->note_data->release (),
- data->note_size, sect_name, buf.data (),
- collect_size));
-
- if (data->note_data == nullptr)
- data->abort_iteration = true;
-}
-
-/* Records the register state of thread PTID out of REGCACHE into the note
- buffer represented by *NOTE_DATA and NOTE_SIZE. OBFD is the bfd into
- which the core file is being created, and STOP_SIGNAL is the signal that
- cause thread PTID to stop. */
-
-static void
-gcore_collect_thread_registers (const struct regcache *regcache,
- ptid_t ptid, bfd *obfd,
- gdb::unique_xmalloc_ptr<char> *note_data,
- int *note_size,
- enum gdb_signal stop_signal)
-{
- struct gdbarch *gdbarch = regcache->arch ();
- gcore_collect_regset_section_cb_data data (gdbarch, regcache, obfd, ptid,
- stop_signal, note_data,
- note_size);
- gdbarch_iterate_over_regset_sections (gdbarch,
- gcore_collect_regset_section_cb,
- &data, regcache);
-}
-
-/* See gcore.h. */
-
-void
-gcore_build_thread_register_notes
- (struct gdbarch *gdbarch, struct thread_info *info, gdb_signal stop_signal,
- bfd *obfd, gdb::unique_xmalloc_ptr<char> *note_data, int *note_size)
-{
- struct regcache *regcache
- = get_thread_arch_regcache (info->inf->process_target (),
- info->ptid, gdbarch);
- target_fetch_registers (regcache, -1);
- gcore_collect_thread_registers (regcache, info->ptid, obfd, note_data,
- note_size, stop_signal);
-}
-
-/* See gcore.h. */
-
-thread_info *
-gcore_find_signalled_thread ()
-{
- thread_info *curr_thr = inferior_thread ();
- if (curr_thr->state != THREAD_EXITED
- && curr_thr->suspend.stop_signal != GDB_SIGNAL_0)
- return curr_thr;
-
- for (thread_info *thr : current_inferior ()->non_exited_threads ())
- if (thr->suspend.stop_signal != GDB_SIGNAL_0)
- return thr;
-
- /* Default to the current thread, unless it has exited. */
- if (curr_thr->state != THREAD_EXITED)
- return curr_thr;
-
- return nullptr;
-}
-
void _initialize_gcore ();
void
_initialize_gcore ()
diff --git a/gdb/gcore.h b/gdb/gcore.h
index ce60841c1a5..af37ff39b41 100644
--- a/gdb/gcore.h
+++ b/gdb/gcore.h
@@ -21,10 +21,6 @@
#define GCORE_H 1
#include "gdb_bfd.h"
-#include "gdbsupport/gdb_signals.h"
-
-struct gdbarch;
-struct thread_info;
extern gdb_bfd_ref_ptr create_gcore_bfd (const char *filename);
extern void write_gcore_file (bfd *obfd);
@@ -32,20 +28,4 @@ extern int objfile_find_memory_regions (struct target_ops *self,
find_memory_region_ftype func,
void *obfd);
-/* Add content to *NOTE_DATA (and update *NOTE_SIZE) to describe the
- registers of thread INFO. Report the thread as having stopped with
- STOP_SIGNAL. The core file is being written to OFD, and GDBARCH is the
- architecture for which the core file is being generated. */
-
-extern void gcore_build_thread_register_notes
- (struct gdbarch *gdbarch, struct thread_info *info, gdb_signal stop_signal,
- bfd *obfd, gdb::unique_xmalloc_ptr<char> *note_data, int *note_size);
-
-/* Find the signalled thread. In case there's more than one signalled
- thread, prefer the current thread, if it is signalled. If no thread was
- signalled, default to the current thread, unless it has exited, in which
- case return NULL. */
-
-extern thread_info *gcore_find_signalled_thread ();
-
#endif /* GCORE_H */
diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c
index 3db4d31de37..e9f8e1b6133 100644
--- a/gdb/linux-tdep.c
+++ b/gdb/linux-tdep.c
@@ -39,7 +39,6 @@
#include "gdb_regex.h"
#include "gdbsupport/enum-flags.h"
#include "gdbsupport/gdb_optional.h"
-#include "gcore.h"
#include <ctype.h>
@@ -1598,6 +1597,104 @@ linux_make_mappings_corefile_notes (struct gdbarch *gdbarch, bfd *obfd,
}
}
+/* Structure for passing information from
+ linux_collect_thread_registers via an iterator to
+ linux_collect_regset_section_cb. */
+
+struct linux_collect_regset_section_cb_data
+{
+ linux_collect_regset_section_cb_data (struct gdbarch *gdbarch,
+ const struct regcache *regcache,
+ bfd *obfd,
+ gdb::unique_xmalloc_ptr<char> ¬e_data,
+ int *note_size,
+ unsigned long lwp,
+ gdb_signal stop_signal)
+ : gdbarch (gdbarch), regcache (regcache), obfd (obfd),
+ note_data (note_data), note_size (note_size), lwp (lwp),
+ stop_signal (stop_signal)
+ {}
+
+ struct gdbarch *gdbarch;
+ const struct regcache *regcache;
+ bfd *obfd;
+ gdb::unique_xmalloc_ptr<char> ¬e_data;
+ int *note_size;
+ unsigned long lwp;
+ enum gdb_signal stop_signal;
+ bool abort_iteration = false;
+};
+
+/* Callback for iterate_over_regset_sections that records a single
+ regset in the corefile note section. */
+
+static void
+linux_collect_regset_section_cb (const char *sect_name, int supply_size,
+ int collect_size, const struct regset *regset,
+ const char *human_name, void *cb_data)
+{
+ struct linux_collect_regset_section_cb_data *data
+ = (struct linux_collect_regset_section_cb_data *) cb_data;
+ bool variable_size_section = (regset != NULL
+ && regset->flags & REGSET_VARIABLE_SIZE);
+
+ if (!variable_size_section)
+ gdb_assert (supply_size == collect_size);
+
+ if (data->abort_iteration)
+ return;
+
+ gdb_assert (regset && regset->collect_regset);
+
+ /* This is intentionally zero-initialized by using std::vector, so
+ that any padding bytes in the core file will show as 0. */
+ std::vector<gdb_byte> buf (collect_size);
+
+ regset->collect_regset (regset, data->regcache, -1, buf.data (),
+ collect_size);
+
+ /* PRSTATUS still needs to be treated specially. */
+ if (strcmp (sect_name, ".reg") == 0)
+ data->note_data.reset (elfcore_write_prstatus
+ (data->obfd, data->note_data.release (),
+ data->note_size, data->lwp,
+ gdb_signal_to_host (data->stop_signal),
+ buf.data ()));
+ else
+ data->note_data.reset (elfcore_write_register_note
+ (data->obfd, data->note_data.release (),
+ data->note_size, sect_name, buf.data (),
+ collect_size));
+
+ if (data->note_data == NULL)
+ data->abort_iteration = true;
+}
+
+/* Records the thread's register state for the corefile note
+ section. */
+
+static void
+linux_collect_thread_registers (const struct regcache *regcache,
+ ptid_t ptid, bfd *obfd,
+ gdb::unique_xmalloc_ptr<char> ¬e_data,
+ int *note_size,
+ enum gdb_signal stop_signal)
+{
+ struct gdbarch *gdbarch = regcache->arch ();
+
+ /* For remote targets the LWP may not be available, so use the TID. */
+ long lwp = ptid.lwp ();
+ if (lwp == 0)
+ lwp = ptid.tid ();
+
+ linux_collect_regset_section_cb_data data (gdbarch, regcache, obfd, note_data,
+ note_size, lwp, stop_signal);
+
+ gdbarch_iterate_over_regset_sections (gdbarch,
+ linux_collect_regset_section_cb,
+ &data, regcache);
+}
+
/* Fetch the siginfo data for the specified thread, if it exists. If
there is no data, or we could not read it, return an empty
buffer. */
@@ -1649,16 +1746,22 @@ static void
linux_corefile_thread (struct thread_info *info,
struct linux_corefile_thread_data *args)
{
- gcore_build_thread_register_notes (args->gdbarch, info, args->stop_signal,
- args->obfd, &args->note_data,
- args->note_size);
+ struct regcache *regcache;
+
+ regcache = get_thread_arch_regcache (info->inf->process_target (),
+ info->ptid, args->gdbarch);
+
+ target_fetch_registers (regcache, -1);
+ gdb::byte_vector siginfo_data = linux_get_siginfo_data (info, args->gdbarch);
+
+ linux_collect_thread_registers (regcache, info->ptid, args->obfd,
+ args->note_data, args->note_size,
+ args->stop_signal);
/* Don't return anything if we got no register information above,
such a core file is useless. */
if (args->note_data != NULL)
{
- gdb::byte_vector siginfo_data
- = linux_get_siginfo_data (info, args->gdbarch);
if (!siginfo_data.empty ())
args->note_data.reset (elfcore_write_note (args->obfd,
args->note_data.release (),
@@ -1857,6 +1960,30 @@ linux_fill_prpsinfo (struct elf_internal_linux_prpsinfo *p)
return 1;
}
+/* Find the signalled thread. In case there's more than one signalled
+ thread, prefer the current thread, if it is signalled. If no
+ thread was signalled, default to the current thread, unless it has
+ exited, in which case return NULL. */
+
+static thread_info *
+find_signalled_thread ()
+{
+ thread_info *curr_thr = inferior_thread ();
+ if (curr_thr->state != THREAD_EXITED
+ && curr_thr->suspend.stop_signal != GDB_SIGNAL_0)
+ return curr_thr;
+
+ for (thread_info *thr : current_inferior ()->non_exited_threads ())
+ if (thr->suspend.stop_signal != GDB_SIGNAL_0)
+ return thr;
+
+ /* Default to the current thread, unless it has exited. */
+ if (curr_thr->state != THREAD_EXITED)
+ return curr_thr;
+
+ return nullptr;
+}
+
/* Build the note section for a corefile, and return it in a malloc
buffer. */
@@ -1894,7 +2021,7 @@ linux_make_corefile_notes (struct gdbarch *gdbarch, bfd *obfd, int *note_size)
/* Like the kernel, prefer dumping the signalled thread first.
"First thread" is what tools use to infer the signalled
thread. */
- thread_info *signalled_thr = gcore_find_signalled_thread ();
+ thread_info *signalled_thr = find_signalled_thread ();
gdb_signal stop_signal;
if (signalled_thr != nullptr)
stop_signal = signalled_thr->suspend.stop_signal;
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